Earth-boring tools are used to form boreholes (e.g., wellbores) in subterranean formations. Such earth-boring tools include, for example, drill bits, reamers, mills, etc. For example, a fixed-cutter earth-boring rotary drill bit (often referred to as a “drag” bit) generally includes a plurality of cutting elements secured to a face of a bit body of the drill bit. A conventional fixed-cutter earth-boring rotary drill bit includes a bit body having generally radially projecting and longitudinally extending blades.
A plurality of cutting elements is positioned on each of the blades. Generally, the cutting elements have either a disk shape or, in some instances, a more elongated, substantially cylindrical shape. The cutting elements commonly comprise a “table” of superabrasive material, such as mutually bound particles of polycrystalline diamond, formed on a supporting substrate of a hard material, such as cemented tungsten carbide. Such cutting elements are often referred to as “polycrystalline diamond compact” (PDC) cutting elements or cutters. The plurality of PDC cutting elements may be fixed within cutting element pockets formed in rotationally leading surfaces of each of the blades. Conventionally, a bonding material such as an adhesive or, more typically, a braze alloy may be used to secure the cutting elements to the bit body.
During drilling operations, the drill bit is positioned at the bottom of a well borehole and rotated. The bit body of a fixed-cutter rotary drill bit may be formed from steel or a composite material, such as a cemented tungsten carbide material. During normal drilling operations, the bit body of the drill bit is exposed to a variety of harsh conditions that can wear the bit body. In order to provide the bit body with increased wear resistance, a hardfacing material is often applied to outer surfaces of the bit body. The hardfacing material may include hard particles of sintered or cast tungsten carbide cemented within a metal alloy binder material. The hardfacing material may be applied as a layer by heating the metal binder material to its liquid state and applying the hardfacing material, with the molten metal binder and the hard particles therein to the surface of the bit body, and allowing the molten metal binder to cool with the hard particles embedded therein. The high temperatures required to apply the hardfacing material to the bit body may cause damage to the diamond portion of PDC cutting elements. Therefore, the PDC cutting elements may be fixed in the cutting element pockets after the hardfacing material has been applied to the bit body.
The increased hardness and wear resistance of hardfacing material makes machining of the hardfacing difficult when using conventional machining techniques, such as drilling, grinding, or milling. As a result, cutting element pockets are generally formed in a bit body prior to applying hardfacing material to the bit body. After forming a cutting element pocket in a bit body, a temporary displacement member may be placed in the cutting element pocket while hardfacing is applied to the bit body in the vicinity of the cutting element pocket, so as to prevent the cutting element pocket from being filled with hardfacing material. After the application of the hardfacing material, the displacement member may be ground out or otherwise removed from the pocket. Thereafter, a cutting element may be secured within the cutting element pocket.